Method of defining excavation limits



Feim. 26, 1957 R. J. HUNDHAUSEN METHOD OF DEFINING EXCAVATION LIMITSFiled Aug. 6. 1954 F I G- 2 JNVENTOR. Robert J Hand/1:10am

United States Patent 0 METHOD OF DEFINING EXCAVATION LIMITS Robert J.Hundhausen, Spokane, Wash, assignor of onehalf to Daniel W. Butner,Spokane, Wash.

Application August 6, 1954, Serial No. 448,404 8 Claims. ,(Cl. 116-114from which the finished grade is determined 'by'measurement employingthe conventional surveyors instrument and leveling rod. Obviously thisrequires considerable time as each reference point must be measured arelatively large number of times by the alternate cut and measure systemuntil the desired grade is reached.

It is therefore another object of this invention to provide a method ofmarking prior to excavation a grade location at grade within theexcavation area thus obviating the requirement of taking measurements atintervals during the course of the work to establish the desired grade.

Another object of the invention lies in the provision of a method ofestablishing limits of excavation to preclude excess excavation ofmaterial which necessitates resultant back filling operation.

Another object of the invention lies in the provision of a method ofdetermining excavation limits wherein the vertical and angular planesurfaces of the finished excavation are initially located and definedand maybe accurately controlled and maintained visually by theexcavating machine operator.

In mining operations it is often found that ores which are economicallyprofitable for mining are visually indistinguishable from ores which arenot profitable. Therefore, under the present mining practice, it isconventional that samples of the mined ore be assayed to determine ifthe operation is producing profitable ores or not. This requiresconsiderable time and also the nearly constant presence of a skilledengineer to direct the mining operation and determine which areas of oreshould be mined and whichshould be left.

It is, therefore, a still further object of this invention to provide amethod of fixing subterranean marks in an area within which anexcavation is contemplated 'so'that certain portions may be excavatedwhen found economically profitable and other portions identified'andleft for subsequent excavation should conditions'cha-nge to render theexcavation of the marginal material profitable.

It is also customary to locate mining claims and other areas on thesurface by means of stakes or other identifying appurtenances whichmaysubsequently be destroyed by fire, vandals etc. and it is thereforeincluded within the scope of this invention and a further object thereoftoprovide a method of marking .areas permanently so 7 they will .not ,beliable to loss :or removal by abnormal activities.

2,782,750 Patented Feb. 26,. 9.57

Another object of the invention lies in the provision of a method offixing boundaries by disposing a substance distinguishable from thesurrounding earth at one or more desired subterranean locations.

These and other objects of the invention will become apparent during thecourse of the following description.

In the accompanying drawings, forming a part of this specification, andin which like numerals are employed to designate like parts, I haveillustrated practices employing the present method. It should beunderstood however that the drawings and description are illustrativeonly and are not intended to limit the invention except insofar as it islimited by the claims.

In the drawings,

Figure 1 is a vertical cross section taken through a portion of a hillupon which a proposed road bed and cut is disclosed in transverse crosssection by dotted lines; and,

Figure 2 is a vertical cross section through a portion of earthincluding a body of ore to be mined.

In brief, the essence of the invention is to form one or more holes inthe earth to a point at or beyond a limit of excavation and then toadmit into the hole one or more materials, distinguishable from thesurrounding earth and the other materials in such a way so as to providemeans for the operator of an excavating machine to visually determinethe progress of the excavation toward the limit and also to visuallydetermine when the limit of excavation is reached.

In carrying out my invention, any means of forming a hole or ofpositioning a distinguishable material at a desired location iscontemplated. The means which most readily come to mind include diamonddrilling, rotary drilling, auger drilling, jet piercing, hammerpercussion drilling, and drive pipe methods. It is not, however,necessary that the holes be round and therefore pits, cuts and trenchesand similar openings may be employed if found desirable. These holes maybe disposed on the vertical or inclined or even on the horizontal wherefound practical. The size and dimensions thereof are relativelyunimportant since only the quantity of filling material is involved.

Referring now more particularly to the drawing, it will be seen inFigure 1 that l have disclosed by broken lines a proposed roadway gradeG which is disposed at a pitch or angle from the horizontal as isconventional on a highway curve and which is provided with aconventional recess draining ditch D at each side from which theupwardly angled walls W of the out ascend.

Prior to excavating, the survey crew will determine the course andelevation as well as pitch of the desired finished grade and as this isdetermined, substantially vertical holes spaced transversely of theroadway are drilled as at 10, 11, and 12, preferably to a point belowthe desired finished grade G. By measurement the holes are thenfilled-with a distinguishable material 13 in the area defined by thebracket c to the finished grade G; then, as in the case of the holes 11and 12, a segment of the hole immediately above the grade and of anydesired length, preferably one or two feet, is filled with a secondmaterial 14 which is distinguishable from the surrounding earth and thefirst material 13. If desired, as indicated in hole 10, no filling isrequired above the grade G or, as indicated in hole 12, no filling abovethe segment b or as an alternative a third distinguishable material 15may be supplied to completely fill the upper segment a of the hole '11.Where the material 15 is exposed through the open mouth of the hole itprovides a means of locating the course of the proposed roadway and also0 :provides the excavating machine operator with means for :gal gingtheprog'ress of the excavation.

So long as the material 15 is being removed while excavating theoperator is aware of the fact that the excavation is two feet (more orless) above the grade G. When the material 14 is found, the operator isaware of the fact that the excavating machine is approaching the grade Gand when the material 14 ceases and the material 13 is found theexcavation is complete to the grade G. As indicated in hole 10, thesegments of the hole above the grade G may be left open in which case itis necessary for the operator to watch for the material 13 and when itis found the excavation is at grade. Obviously the segments a, b, andmay be of equal length and also there may be a greater number ofsegments above grade if desired and a plurality of materialsdistinguishable from the surrounding earth and each other may beemployed (say to each one foot segment) and the depth of the excavationmay then be accurately determined at any time by the material found inthe hole during the operation.

It is obvious from this description that the pitch of the road may becontrolled by measurement during the original surveying and drilling andsubsequent surveying measurements will not be required since a fixedmark is disposed within the excavation area enabling the operator toaccurately gauge the amount of earth to be removed from the excavation.

As in the case of the hole 16 which is drilled only to the grade or wallline, the material 14 is supplied in the lower portion or all of thehole 16 and when the excavator runs out of this material he knows theexcavation is complete to the wall W or grade G.

The materials indicated by reference numerals 13, 14, and are obviouslyisolated insofar as any grid or network is concerned and may bedistinguishable by any known means, such as by color, texture,substance, electronics, magnetically, etc. Primarily the materialsshould be relatively inexpensive and for this reason it is contemplatedemploying natural or artificially colored materials such as rock, soils,organic compounds or manufactured materials. Of these limestone forwhite or varicolored material; various colored sandstones including red,green and other colors; shales, coals, magnetite sands, limonite orochre soils, or if it is not convenient to secure these, crushed rocksof the immediate area as well as sand or other substances plentiful inthe area may be employed. It is also contemplated using the cuttingsremoved from the hole during drilling by treating them with dyes orother additives or reagents to effect permanent color change or bodysubstance. It is also contemplated to use a brittle or friable concreteor setting agent that will not be ditfused in soil such as sand 9 orflour dust and which may be easily removed by the excavating machine.

The invention further contemplates the use of radio active or magneticmaterials to assist in locating holes provided for permanent referencepoints or for subsequent location where the flora or other action maydisguise or cover a visual material, the latter being primarily ofinterest in locating survey corners, claim stakes and other referencepoints infrequently used and often diflicult to locate. The fillingmaterials may also be provided with a radio active tracer material toassist in location, or the lower filler material 13 may alone contain aradio active tracer material which will actuate a Geiger counter on theexcavating machine to indicate when the grade depth is approached orreached.

The material may be introduced into the hole in any convenient manner,tamped to the proper grade level or elevation or it may flow freelywhere the grade construction may be within substantial limits.

In mining operations the use of the present method of definingexcavation limits is obvious for open pit mining to define economicallyprofitable ores for removal. However, it is also contemplated employingthe method for tunnel or cave mining wherein the ore is caved from abody into hoppers from which the ore is discharged into cars and removedfrom the mine. In this type mining it is required that the cavingprocess not proceed upwardly to a point where the surface is disturbedsince slides are then likely to occur. As indicated in Figure 2 of thedrawing it is therefore effective to drill vertical or angular holessuch as 17 from the surface S into the ore body 0 to a depth wherein theremaining earth is sufficient to support the surface against caving. Theholes 17 are then filled with a material distinguishable from the oreand surrounding earth so that as the ore is removed from within theearth and caved downwardly and the limit indicated by dotted line L isreached, the lower end of the hole 17 is opened and the distinguishablematerial is found in the caved material and further upward removal ofore is terminated when so found. Under the present conventional methodit is necessary for an engineer to continually measure and survey thecaving process to determine where the point of danger is likely to occurand stop the mining operations at that point.

Many ore deposits are limited not by structural conditions but by whatis known as assay walls. These boundaries of a mineable deposit aredetermined by drilling and assaying. When a deposit has assay walls theboudaries of ore are limited by economic conditions determined by costof mining and metal prices. Mining conditions change from year to yearcausing boundaries to extend as metal prices increase or mining costsdecrease. The grade of the ore, however, does not change. The holesdrilled for assay purposes may be preserved as a permanent field assayrecord by filling these holes with various colored materials and arecord or log thereof maintained in the office. Thereafter in thefuture, mining can be extended into these marginal areas withoutadditional engineering survey work in the field to relocate holes anddetermine assay limits by study or additional drilling and sampling. Inthis way, when the marginal ore becomes profitable to mine the miningmay be extended into the ores defined by a distinguishable, say red,filler material previously located and should mining costs permit, evenlater the mining may continue into even the lower grade ore which wouldbe defined by a still further distinguishable material. Here again atrace of radio active material or magnetized material near the mouth ofthe hole may be incorporated to assist in future location of the hole byGeiger counter or compass.

Having thus described my invention, I claim:

1. The method of defining excavation limits which consists in drilling anumber of holes in the earth on planes defining selected ones of theexcavation limits and to points beyond the excavation depth limit,depositing in the hole a material distinguishable from the surroundingearth in quantity to fill the hole to the excavation depth limit, andthen depositing a second material distinguishable from the surroundingearth and the first named material for a portion of the balance of thehole, and then filling the balance of the hole with a third materialdistinguishable from the surrounding earth and the first and secondnamed materials.

2. The method of defining excavation limits which consists in forming atleast one hole in the earth to a point beyond the excavation limit,depositing in the hole a material distinguishable from the surroundingearth in quantity to fill the hole to the excavation limit, subsequentlydepositing a second material distinguishable from the surrounding earthand the first named material for a portion of the balance of the hole,and then filling the balance of the hole with a third materialdistinguishable from the surrounding earth and the first two namedmaterials.

3. The method of defining excavation limits which consists in drilling anumber of holes in the earth on the planes defining selected ones of theexcavation limits and to points beyond the excavation depth limit,depositing in the hole a substance distinguishable from the surround- 5ing earth in quantity to fill the hole to the excavation depth limit,and then filling the balance of the hole with a second materialdistinguishable from the surrounding earth and the first named material.

4. The method of defining excavation limits which consists in forming atleast one hole in the earth to a point beyond the excavation limit,depositing in the hole a material distinguishable from the surroundingearth in quantity to fill the hole to the excavation limit, and thendepositing in the hole a second material distinguishable from thesurrounding earth and the first named material.

5. The method of defining excavation limits which consists in forming atleast one hole in the earth to a point substantially equal to theexcavation limit, and then depositing in the hole an isolated materialdistingishable from the surrounding earth.

6. In a method of marking a subterranean location the step whichconsists in disposing at a desired subtcrranean location an isolatedfriable substance distinguishable from the surrounding earth.

7. The method of defining excavation limits which consists in drilling anumber of holes in the earth to a point beyond the excavation limit,then filling the hole to the excavation limit with a materialdistinguishable from the surrounding earth, and then completely fillingthe hole in equal segments with a plurality of materials distinguishablefrom the surrounding earth and each other material.

8. The method of defining excavation limits which consists in forming atleast one hole in the earth to a point beyond the excavation limit, anddepositing in the hole an isolated material distinguishable from thesurrounding earth in quantity to fill the hole to the excavation limit.

References Cited in the file of this patent UNITED STATES PATENTS2,131,291 Maust Sept. 27, 1938 2,276,306 Hoover Mar. 17, 1942 2,340,770Reichert Feb. 1, 1944 2,521,745 Pope Sept. 12, 1950 2,660,822 HargusDec. 1, 1953

